Teach git-fetch to exploit server side automatic tag following
[git/gitweb.git] / builtin-fetch.c
blob55f611e3c26e55df43eca1f40df74d335c850cc0
1 /*
2 * "git fetch"
3 */
4 #include "cache.h"
5 #include "refs.h"
6 #include "commit.h"
7 #include "builtin.h"
8 #include "path-list.h"
9 #include "remote.h"
10 #include "transport.h"
11 #include "run-command.h"
12 #include "parse-options.h"
14 static const char * const builtin_fetch_usage[] = {
15 "git-fetch [options] [<repository> <refspec>...]",
16 NULL
19 enum {
20 TAGS_UNSET = 0,
21 TAGS_DEFAULT = 1,
22 TAGS_SET = 2
25 static int append, force, keep, update_head_ok, verbose, quiet;
26 static int tags = TAGS_DEFAULT;
27 static const char *depth;
28 static const char *upload_pack;
29 static struct strbuf default_rla = STRBUF_INIT;
30 static struct transport *transport;
32 static struct option builtin_fetch_options[] = {
33 OPT__QUIET(&quiet),
34 OPT__VERBOSE(&verbose),
35 OPT_BOOLEAN('a', "append", &append,
36 "append to .git/FETCH_HEAD instead of overwriting"),
37 OPT_STRING(0, "upload-pack", &upload_pack, "PATH",
38 "path to upload pack on remote end"),
39 OPT_BOOLEAN('f', "force", &force,
40 "force overwrite of local branch"),
41 OPT_SET_INT('t', "tags", &tags,
42 "fetch all tags and associated objects", TAGS_SET),
43 OPT_BOOLEAN('k', "keep", &keep, "keep downloaded pack"),
44 OPT_BOOLEAN('u', "update-head-ok", &update_head_ok,
45 "allow updating of HEAD ref"),
46 OPT_STRING(0, "depth", &depth, "DEPTH",
47 "deepen history of shallow clone"),
48 OPT_END()
51 static void unlock_pack(void)
53 if (transport)
54 transport_unlock_pack(transport);
57 static void unlock_pack_on_signal(int signo)
59 unlock_pack();
60 signal(SIGINT, SIG_DFL);
61 raise(signo);
64 static void add_merge_config(struct ref **head,
65 const struct ref *remote_refs,
66 struct branch *branch,
67 struct ref ***tail)
69 int i;
71 for (i = 0; i < branch->merge_nr; i++) {
72 struct ref *rm, **old_tail = *tail;
73 struct refspec refspec;
75 for (rm = *head; rm; rm = rm->next) {
76 if (branch_merge_matches(branch, i, rm->name)) {
77 rm->merge = 1;
78 break;
81 if (rm)
82 continue;
85 * Not fetched to a tracking branch? We need to fetch
86 * it anyway to allow this branch's "branch.$name.merge"
87 * to be honored by git-pull, but we do not have to
88 * fail if branch.$name.merge is misconfigured to point
89 * at a nonexisting branch. If we were indeed called by
90 * git-pull, it will notice the misconfiguration because
91 * there is no entry in the resulting FETCH_HEAD marked
92 * for merging.
94 refspec.src = branch->merge[i]->src;
95 refspec.dst = NULL;
96 refspec.pattern = 0;
97 refspec.force = 0;
98 get_fetch_map(remote_refs, &refspec, tail, 1);
99 for (rm = *old_tail; rm; rm = rm->next)
100 rm->merge = 1;
104 static void find_non_local_tags(struct transport *transport,
105 struct ref **head,
106 struct ref ***tail);
108 static struct ref *get_ref_map(struct transport *transport,
109 struct refspec *refs, int ref_count, int tags,
110 int *autotags)
112 int i;
113 struct ref *rm;
114 struct ref *ref_map = NULL;
115 struct ref **tail = &ref_map;
117 const struct ref *remote_refs = transport_get_remote_refs(transport);
119 if (ref_count || tags == TAGS_SET) {
120 for (i = 0; i < ref_count; i++) {
121 get_fetch_map(remote_refs, &refs[i], &tail, 0);
122 if (refs[i].dst && refs[i].dst[0])
123 *autotags = 1;
125 /* Merge everything on the command line, but not --tags */
126 for (rm = ref_map; rm; rm = rm->next)
127 rm->merge = 1;
128 if (tags == TAGS_SET) {
129 struct refspec refspec;
130 refspec.src = "refs/tags/";
131 refspec.dst = "refs/tags/";
132 refspec.pattern = 1;
133 refspec.force = 0;
134 get_fetch_map(remote_refs, &refspec, &tail, 0);
136 } else {
137 /* Use the defaults */
138 struct remote *remote = transport->remote;
139 struct branch *branch = branch_get(NULL);
140 int has_merge = branch_has_merge_config(branch);
141 if (remote && (remote->fetch_refspec_nr || has_merge)) {
142 for (i = 0; i < remote->fetch_refspec_nr; i++) {
143 get_fetch_map(remote_refs, &remote->fetch[i], &tail, 0);
144 if (remote->fetch[i].dst &&
145 remote->fetch[i].dst[0])
146 *autotags = 1;
147 if (!i && !has_merge && ref_map &&
148 !remote->fetch[0].pattern)
149 ref_map->merge = 1;
152 * if the remote we're fetching from is the same
153 * as given in branch.<name>.remote, we add the
154 * ref given in branch.<name>.merge, too.
156 if (has_merge &&
157 !strcmp(branch->remote_name, remote->name))
158 add_merge_config(&ref_map, remote_refs, branch, &tail);
159 } else {
160 ref_map = get_remote_ref(remote_refs, "HEAD");
161 if (!ref_map)
162 die("Couldn't find remote ref HEAD");
163 ref_map->merge = 1;
164 tail = &ref_map->next;
167 if (tags == TAGS_DEFAULT && *autotags)
168 find_non_local_tags(transport, &ref_map, &tail);
169 ref_remove_duplicates(ref_map);
171 return ref_map;
174 static int s_update_ref(const char *action,
175 struct ref *ref,
176 int check_old)
178 char msg[1024];
179 char *rla = getenv("GIT_REFLOG_ACTION");
180 static struct ref_lock *lock;
182 if (!rla)
183 rla = default_rla.buf;
184 snprintf(msg, sizeof(msg), "%s: %s", rla, action);
185 lock = lock_any_ref_for_update(ref->name,
186 check_old ? ref->old_sha1 : NULL, 0);
187 if (!lock)
188 return 1;
189 if (write_ref_sha1(lock, ref->new_sha1, msg) < 0)
190 return 1;
191 return 0;
194 #define SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)
195 #define REFCOL_WIDTH 10
197 static int update_local_ref(struct ref *ref,
198 const char *remote,
199 int verbose,
200 char *display)
202 struct commit *current = NULL, *updated;
203 enum object_type type;
204 struct branch *current_branch = branch_get(NULL);
205 const char *pretty_ref = ref->name + (
206 !prefixcmp(ref->name, "refs/heads/") ? 11 :
207 !prefixcmp(ref->name, "refs/tags/") ? 10 :
208 !prefixcmp(ref->name, "refs/remotes/") ? 13 :
211 *display = 0;
212 type = sha1_object_info(ref->new_sha1, NULL);
213 if (type < 0)
214 die("object %s not found", sha1_to_hex(ref->new_sha1));
216 if (!*ref->name) {
217 /* Not storing */
218 if (verbose)
219 sprintf(display, "* branch %s -> FETCH_HEAD", remote);
220 return 0;
223 if (!hashcmp(ref->old_sha1, ref->new_sha1)) {
224 if (verbose)
225 sprintf(display, "= %-*s %-*s -> %s", SUMMARY_WIDTH,
226 "[up to date]", REFCOL_WIDTH, remote,
227 pretty_ref);
228 return 0;
231 if (current_branch &&
232 !strcmp(ref->name, current_branch->name) &&
233 !(update_head_ok || is_bare_repository()) &&
234 !is_null_sha1(ref->old_sha1)) {
236 * If this is the head, and it's not okay to update
237 * the head, and the old value of the head isn't empty...
239 sprintf(display, "! %-*s %-*s -> %s (can't fetch in current branch)",
240 SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
241 pretty_ref);
242 return 1;
245 if (!is_null_sha1(ref->old_sha1) &&
246 !prefixcmp(ref->name, "refs/tags/")) {
247 sprintf(display, "- %-*s %-*s -> %s",
248 SUMMARY_WIDTH, "[tag update]", REFCOL_WIDTH, remote,
249 pretty_ref);
250 return s_update_ref("updating tag", ref, 0);
253 current = lookup_commit_reference_gently(ref->old_sha1, 1);
254 updated = lookup_commit_reference_gently(ref->new_sha1, 1);
255 if (!current || !updated) {
256 const char *msg;
257 const char *what;
258 if (!strncmp(ref->name, "refs/tags/", 10)) {
259 msg = "storing tag";
260 what = "[new tag]";
262 else {
263 msg = "storing head";
264 what = "[new branch]";
267 sprintf(display, "* %-*s %-*s -> %s", SUMMARY_WIDTH, what,
268 REFCOL_WIDTH, remote, pretty_ref);
269 return s_update_ref(msg, ref, 0);
272 if (in_merge_bases(current, &updated, 1)) {
273 char quickref[83];
274 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
275 strcat(quickref, "..");
276 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
277 sprintf(display, " %-*s %-*s -> %s", SUMMARY_WIDTH, quickref,
278 REFCOL_WIDTH, remote, pretty_ref);
279 return s_update_ref("fast forward", ref, 1);
280 } else if (force || ref->force) {
281 char quickref[84];
282 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
283 strcat(quickref, "...");
284 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
285 sprintf(display, "+ %-*s %-*s -> %s (forced update)",
286 SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote, pretty_ref);
287 return s_update_ref("forced-update", ref, 1);
288 } else {
289 sprintf(display, "! %-*s %-*s -> %s (non fast forward)",
290 SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
291 pretty_ref);
292 return 1;
296 static int store_updated_refs(const char *url, struct ref *ref_map)
298 FILE *fp;
299 struct commit *commit;
300 int url_len, i, note_len, shown_url = 0;
301 char note[1024];
302 const char *what, *kind;
303 struct ref *rm;
304 char *filename = git_path("FETCH_HEAD");
306 fp = fopen(filename, "a");
307 if (!fp)
308 return error("cannot open %s: %s\n", filename, strerror(errno));
309 for (rm = ref_map; rm; rm = rm->next) {
310 struct ref *ref = NULL;
312 if (rm->peer_ref) {
313 ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
314 strcpy(ref->name, rm->peer_ref->name);
315 hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
316 hashcpy(ref->new_sha1, rm->old_sha1);
317 ref->force = rm->peer_ref->force;
320 commit = lookup_commit_reference_gently(rm->old_sha1, 1);
321 if (!commit)
322 rm->merge = 0;
324 if (!strcmp(rm->name, "HEAD")) {
325 kind = "";
326 what = "";
328 else if (!prefixcmp(rm->name, "refs/heads/")) {
329 kind = "branch";
330 what = rm->name + 11;
332 else if (!prefixcmp(rm->name, "refs/tags/")) {
333 kind = "tag";
334 what = rm->name + 10;
336 else if (!prefixcmp(rm->name, "refs/remotes/")) {
337 kind = "remote branch";
338 what = rm->name + 13;
340 else {
341 kind = "";
342 what = rm->name;
345 url_len = strlen(url);
346 for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
348 url_len = i + 1;
349 if (4 < i && !strncmp(".git", url + i - 3, 4))
350 url_len = i - 3;
352 note_len = 0;
353 if (*what) {
354 if (*kind)
355 note_len += sprintf(note + note_len, "%s ",
356 kind);
357 note_len += sprintf(note + note_len, "'%s' of ", what);
359 note_len += sprintf(note + note_len, "%.*s", url_len, url);
360 fprintf(fp, "%s\t%s\t%s\n",
361 sha1_to_hex(commit ? commit->object.sha1 :
362 rm->old_sha1),
363 rm->merge ? "" : "not-for-merge",
364 note);
366 if (ref) {
367 update_local_ref(ref, what, verbose, note);
368 if (*note) {
369 if (!shown_url) {
370 fprintf(stderr, "From %.*s\n",
371 url_len, url);
372 shown_url = 1;
374 fprintf(stderr, " %s\n", note);
378 fclose(fp);
379 return 0;
383 * We would want to bypass the object transfer altogether if
384 * everything we are going to fetch already exists and connected
385 * locally.
387 * The refs we are going to fetch are in to_fetch (nr_heads in
388 * total). If running
390 * $ git-rev-list --objects to_fetch[0] to_fetch[1] ... --not --all
392 * does not error out, that means everything reachable from the
393 * refs we are going to fetch exists and is connected to some of
394 * our existing refs.
396 static int quickfetch(struct ref *ref_map)
398 struct child_process revlist;
399 struct ref *ref;
400 char **argv;
401 int i, err;
404 * If we are deepening a shallow clone we already have these
405 * objects reachable. Running rev-list here will return with
406 * a good (0) exit status and we'll bypass the fetch that we
407 * really need to perform. Claiming failure now will ensure
408 * we perform the network exchange to deepen our history.
410 if (depth)
411 return -1;
413 for (i = 0, ref = ref_map; ref; ref = ref->next)
414 i++;
415 if (!i)
416 return 0;
418 argv = xmalloc(sizeof(*argv) * (i + 6));
419 i = 0;
420 argv[i++] = xstrdup("rev-list");
421 argv[i++] = xstrdup("--quiet");
422 argv[i++] = xstrdup("--objects");
423 for (ref = ref_map; ref; ref = ref->next)
424 argv[i++] = xstrdup(sha1_to_hex(ref->old_sha1));
425 argv[i++] = xstrdup("--not");
426 argv[i++] = xstrdup("--all");
427 argv[i++] = NULL;
429 memset(&revlist, 0, sizeof(revlist));
430 revlist.argv = (const char**)argv;
431 revlist.git_cmd = 1;
432 revlist.no_stdin = 1;
433 revlist.no_stdout = 1;
434 revlist.no_stderr = 1;
435 err = run_command(&revlist);
437 for (i = 0; argv[i]; i++)
438 free(argv[i]);
439 free(argv);
440 return err;
443 static int fetch_refs(struct transport *transport, struct ref *ref_map)
445 int ret = quickfetch(ref_map);
446 if (ret)
447 ret = transport_fetch_refs(transport, ref_map);
448 if (!ret)
449 ret |= store_updated_refs(transport->url, ref_map);
450 transport_unlock_pack(transport);
451 return ret;
454 static int add_existing(const char *refname, const unsigned char *sha1,
455 int flag, void *cbdata)
457 struct path_list *list = (struct path_list *)cbdata;
458 path_list_insert(refname, list);
459 return 0;
462 static int will_fetch(struct ref **head, const unsigned char *sha1)
464 struct ref *rm = *head;
465 while (rm) {
466 if (!hashcmp(rm->old_sha1, sha1))
467 return 1;
468 rm = rm->next;
470 return 0;
473 static void find_non_local_tags(struct transport *transport,
474 struct ref **head,
475 struct ref ***tail)
477 struct path_list existing_refs = { NULL, 0, 0, 0 };
478 struct path_list new_refs = { NULL, 0, 0, 1 };
479 char *ref_name;
480 int ref_name_len;
481 const unsigned char *ref_sha1;
482 const struct ref *tag_ref;
483 struct ref *rm = NULL;
484 const struct ref *ref;
486 for_each_ref(add_existing, &existing_refs);
487 for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
488 if (prefixcmp(ref->name, "refs/tags"))
489 continue;
491 ref_name = xstrdup(ref->name);
492 ref_name_len = strlen(ref_name);
493 ref_sha1 = ref->old_sha1;
495 if (!strcmp(ref_name + ref_name_len - 3, "^{}")) {
496 ref_name[ref_name_len - 3] = 0;
497 tag_ref = transport_get_remote_refs(transport);
498 while (tag_ref) {
499 if (!strcmp(tag_ref->name, ref_name)) {
500 ref_sha1 = tag_ref->old_sha1;
501 break;
503 tag_ref = tag_ref->next;
507 if (!path_list_has_path(&existing_refs, ref_name) &&
508 !path_list_has_path(&new_refs, ref_name) &&
509 (has_sha1_file(ref->old_sha1) ||
510 will_fetch(head, ref->old_sha1))) {
511 path_list_insert(ref_name, &new_refs);
513 rm = alloc_ref(strlen(ref_name) + 1);
514 strcpy(rm->name, ref_name);
515 rm->peer_ref = alloc_ref(strlen(ref_name) + 1);
516 strcpy(rm->peer_ref->name, ref_name);
517 hashcpy(rm->old_sha1, ref_sha1);
519 **tail = rm;
520 *tail = &rm->next;
522 free(ref_name);
524 path_list_clear(&existing_refs, 0);
525 path_list_clear(&new_refs, 0);
528 static int do_fetch(struct transport *transport,
529 struct refspec *refs, int ref_count)
531 struct ref *ref_map;
532 struct ref *rm;
533 int autotags = (transport->remote->fetch_tags == 1);
534 if (transport->remote->fetch_tags == 2 && tags != TAGS_UNSET)
535 tags = TAGS_SET;
536 if (transport->remote->fetch_tags == -1)
537 tags = TAGS_UNSET;
539 if (!transport->get_refs_list || !transport->fetch)
540 die("Don't know how to fetch from %s", transport->url);
542 /* if not appending, truncate FETCH_HEAD */
543 if (!append) {
544 char *filename = git_path("FETCH_HEAD");
545 FILE *fp = fopen(filename, "w");
546 if (!fp)
547 return error("cannot open %s: %s\n", filename, strerror(errno));
548 fclose(fp);
551 ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
553 for (rm = ref_map; rm; rm = rm->next) {
554 if (rm->peer_ref)
555 read_ref(rm->peer_ref->name, rm->peer_ref->old_sha1);
558 if (tags == TAGS_DEFAULT && autotags)
559 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
560 if (fetch_refs(transport, ref_map)) {
561 free_refs(ref_map);
562 return 1;
564 free_refs(ref_map);
566 /* if neither --no-tags nor --tags was specified, do automated tag
567 * following ... */
568 if (tags == TAGS_DEFAULT && autotags) {
569 struct ref **tail = &ref_map;
570 ref_map = NULL;
571 find_non_local_tags(transport, &ref_map, &tail);
572 if (ref_map) {
573 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
574 transport_set_option(transport, TRANS_OPT_DEPTH, "0");
575 fetch_refs(transport, ref_map);
577 free_refs(ref_map);
580 transport_disconnect(transport);
582 return 0;
585 static void set_option(const char *name, const char *value)
587 int r = transport_set_option(transport, name, value);
588 if (r < 0)
589 die("Option \"%s\" value \"%s\" is not valid for %s\n",
590 name, value, transport->url);
591 if (r > 0)
592 warning("Option \"%s\" is ignored for %s\n",
593 name, transport->url);
596 int cmd_fetch(int argc, const char **argv, const char *prefix)
598 struct remote *remote;
599 int i;
600 static const char **refs = NULL;
601 int ref_nr = 0;
603 /* Record the command line for the reflog */
604 strbuf_addstr(&default_rla, "fetch");
605 for (i = 1; i < argc; i++)
606 strbuf_addf(&default_rla, " %s", argv[i]);
608 argc = parse_options(argc, argv,
609 builtin_fetch_options, builtin_fetch_usage, 0);
611 if (argc == 0)
612 remote = remote_get(NULL);
613 else
614 remote = remote_get(argv[0]);
616 transport = transport_get(remote, remote->url[0]);
617 if (verbose >= 2)
618 transport->verbose = 1;
619 if (quiet)
620 transport->verbose = -1;
621 if (upload_pack)
622 set_option(TRANS_OPT_UPLOADPACK, upload_pack);
623 if (keep)
624 set_option(TRANS_OPT_KEEP, "yes");
625 if (depth)
626 set_option(TRANS_OPT_DEPTH, depth);
628 if (!transport->url)
629 die("Where do you want to fetch from today?");
631 if (argc > 1) {
632 int j = 0;
633 refs = xcalloc(argc + 1, sizeof(const char *));
634 for (i = 1; i < argc; i++) {
635 if (!strcmp(argv[i], "tag")) {
636 char *ref;
637 i++;
638 ref = xmalloc(strlen(argv[i]) * 2 + 22);
639 strcpy(ref, "refs/tags/");
640 strcat(ref, argv[i]);
641 strcat(ref, ":refs/tags/");
642 strcat(ref, argv[i]);
643 refs[j++] = ref;
644 } else
645 refs[j++] = argv[i];
647 refs[j] = NULL;
648 ref_nr = j;
651 signal(SIGINT, unlock_pack_on_signal);
652 atexit(unlock_pack);
653 return do_fetch(transport, parse_ref_spec(ref_nr, refs), ref_nr);